Non-mydriatic, non-contact system and method for performing widefield fundus photographic imaging of the eye

Abstract

A non-mydriatic, non-contact ultra-widefield fundus (u-WF) photographic imaging system and method are provided for performing u-WF photographic imaging of the eye. The non-mydriatic, non-contact u-WF photographic imaging system includes an illumination system that delivers trans-pars-planar illumination to the eyeball. This frees the entire pupil to be used for imaging. Freeing the entire pupil to be used for imaging allows a u-WFC of the non-mydriatic, non-contact u-WF photographic imaging system to use a relatively simple optics system to capture an ultra-wide FOV. Eliminating the need to dilate the pupil and the need to make contact with the eye while performing imaging eliminates the many problems associated with mydriatic, contact-mode fundus imaging systems and methods. In addition, the system can be implemented in a way that makes it highly suitable for telemedicine applications in underserved areas where clinics and trained healthcare providers may not be available.

What is claimed is: 
     
       1. A non-mydriatic, non-contact ultra-widefield fundus (u-WF) photographic imaging system for imaging an eye, the system comprising:
 an illumination system comprising:
 at least a first light source, the first light source generating light of at least a first wavelength range; 
 a first optics system, the first optics system being configured to convert the light into a first light beam having a first predetermined shape and size, the first optics system including at least a first optical element that is spaced a predetermined distance away from an eyeball to avoid physical contact with the eyeball and with an eyelid of the eye, the first optical element being configured to couple the first light beam onto a pars plana area of an eyeball, wherein the first optics system includes at least an aperture element having an annular-arc shape to cause the first predetermined shape of the first light beam to substantially match a shape of the pars plana area of the eyeball, wherein the aperture element is configured to be positioned between the first optical element and the pars plana area of the eyeball; 
 at least a second light source of a second optics system, the second light source generating light of at least a second wavelength range during an alignment process of the first optics system between the pars plana area and the first optical element of the first optics system; 
 at least a second optical element of the second optics system arranged with respect to the second light source to couple at least a portion of the light of the second wavelength range through a pupil of the eye to illuminate a posterior region of the eyeball during the alignment process of the first optics system, wherein at least a portion of the light of the second wavelength range that illuminates the posterior region is scattered from the posterior region onto a sclera of the eyeball; and 
 a second optical sensor array positioned to receive at least a portion of the light scattered onto the sclera and configured to produce a second image from the portion of the scattered light received thereby, the second image containing information relating to the alignment between the pars plana area and the first optical element of the first optics system; and 
 
 at least a processor configured to process the second image to determine whether the first optical element is properly aligned with the pars plana area and to output a first control signal; and 
 at least a first motorized stage mechanically coupled to the first optical element, the first motorized stage receiving the first control signal and adjusting a spatial position of the first optical element to improve alignment between the first optical element and the pars plana area. 
 
     
     
       2. The non-mydriatic, non-contact u-WF photographic imaging system of  claim 1 , wherein the second light source is a near-infrared (NIR) light source and the second wavelength range is an NIR wavelength range. 
     
     
       3. The non-mydriatic, non-contact u-WF photographic imaging system of  claim 2 , wherein the first light source generates white light and the first wavelength range includes wavelengths in a visible spectrum. 
     
     
       4. The non-mydriatic, non-contact u-WF photographic imaging system of  claim 3 , wherein the first light source comprises a red light source that generates red light, a green light source that generates green light and a blue light source that generates blue light, the first optics system combining the red light, the green light and the blue light to produce the white light. 
     
     
       5. The non-mydriatic, non-contact u-WF photographic imaging system of  claim 4 , further comprising:
 an imaging system comprising:
 a second optics system, the second optics system being configured to receive light at the first wavelength range passing out of a pupil of the eyeball over an ultra-wide field of view (FOV) and to direct at least a portion of the received light in a first direction; and 
 a first camera, the first camera having a first optical sensor array, at least a portion of the light at the first wavelength range directed in the first direction being incident on the first optical sensor array, the first optical sensor array being configured to produce a first fundus photographic image from the incident light, 
 
 wherein said at least a processor is configured to process the first fundus photographic image and, if necessary, to make an adjustment to an amount of electrical power delivered to at least one of the red, green and blue light sources in order to control relative percentages of red, green and blue light that are combined by the first optics system to produce the white light. 
 
     
     
       6. The non-mydriatic, non-contact u-WF photographic imaging system of  claim 5 , wherein the first camera is a camera of a smartphone. 
     
     
       7. The non-mydriatic, non-contact u-WF photographic imaging system of  claim 5 , wherein the first camera reduces exposure time to avoid blur. 
     
     
       8. The non-mydriatic, non-contact u-WF photographic imaging system of  claim 1 , wherein the second light source is a near-infrared (NIR) light source and the second wavelength range is an NIR wavelength range. 
     
     
       9. The non-mydriatic, non-contact u-WF photographic imaging system of  claim 8 , wherein the first light source generates white light and the first wavelength range includes wavelengths in a visible spectrum. 
     
     
       10. The non-mydriatic, non-contact u-WF photographic imaging system of  claim 9 , wherein the first light source comprises a red light source that generates red light, a green light source that generates green light and a blue light source that generates blue light, the first optics system combining the red light, the green light and the blue light to produce the white light. 
     
     
       11. The non-mydriatic, non-contact u-WF photographic imaging system of  claim 10 , further comprising:
 an imaging system comprising:
 a second optics system, the second optics system being configured to receive light at the first wavelength range passing out of a pupil of the eyeball over an ultra-wide field of view (FOV) and to direct at least a portion of the received light in a first direction; and 
 a first camera, the first camera having a first optical sensor array, at least a portion of the light at the first wavelength range directed in the first direction being incident on the first optical sensor array, the first optical sensor array being configured to produce a first fundus photographic image from the incident light, 
 
 wherein said at least a processor is configured to process the first fundus photographic image and, if necessary, to make an adjustment to an amount of electrical power delivered to at least one of the red, green and blue light sources in order to control relative percentages of red, green and blue light that are combined by the first optics system to produce the white light. 
 
     
     
       12. The non-mydriatic, non-contact u-WF photographic imaging system of  claim 1 , wherein the first optical element is a lens. 
     
     
       13. A non-mydriatic, non-contact u-WF photographic imaging system, comprising:
 an illumination system comprising:
 at least a first light source, the first light source generating light of at least a first wavelength range; 
 a first optics system, the first optics system being configured to convert the light into a first light beam having a first predetermined shape and size, the first optics system including at least a first optical element that is spaced a predetermined distance away from an eyeball to avoid physical contact with the eyeball and with an eyelid of the eye, the first optical element being configured to couple the first light beam onto a pars plana area of an eyeball, wherein the first optics system includes at least an aperture element having an annular-arc shape to cause the first predetermined shape of the first light beam to substantially match a shape of the pars plana area of the eyeball, wherein the aperture element is configured to be positioned between the first optical element and the pars plana area of the eyeball; 
 
 an imaging system comprising:
 a second optics system, the second optics system being configured to receive light at the first wavelength range passing out of a pupil of the eyeball over an ultra-wide field of view (FOV) and to direct at least a portion of the received light in a first direction; and 
 a first camera, the first camera having a first optical sensor array, at least a portion of the light at the first wavelength range directed in the first direction being incident on the first optical sensor array, the first optical sensor array being configured to produce a first fundus photographic image from the incident light; and 
 
 at least a processor configured to process a series of the first fundus photographic images produced by the first optical sensor array at multiple instants in time associated with multiple respective spatial positions of the first optical element of the first optics system to determine which of the spatial positions resulted in proper alignment between the pars plana area and the first optical element and to output a first control signal; and 
 at least a first motorized stage mechanically coupled to the first optical element, the first motorized stage receiving the first control signal and, if the first control signal indicates that the first optical element is not properly aligned with the pars plana area, moving the first optical element to the spatial position that resulted in proper alignment between the first optical element and the pars plana area. 
 
     
     
       14. A method for performing non-mydriatic, non-contact ultra-widefield fundus (u-WF) photographic imaging of an eye, the method comprising:
 with at least a first light source, generating light of at least a first wavelength range; 
 with a first optics system, converting the light into a first light beam having a first predetermined shape and size, the first optics system including at least a first optical element that is spaced a predetermined distance away from an eyeball to avoid physical contact with the eyeball and with an eyelid of the eye, wherein the first optics system further includes an aperture element having an annular-arc shape to cause the first predetermined shape of the first light beam to substantially match a shape of a pars plana area of the eyeball, wherein the aperture element is positioned between the first optical element and the pars plana area of the eyeball; 
 with the first optical element, coupling the first light beam onto the pars plana area of an eyeball; 
 with a second optics system, receiving light at the first wavelength range passing out of a pupil of the eyeball over an ultra-wide field of view (FOV) and directing at least a portion of the received light in a first direction; 
 with a first optical sensor array of a first camera, receiving at least a portion of the light at the first wavelength range directed in the first direction and producing a first fundus photographic image from the light received by the first optical sensor array; 
 with at least a second light source, generating light of at least a second wavelength range during an alignment process of the first optics system between the pars plana area and the first optical element of the first optics system; and 
 with at least a second optical element of a second optics system, coupling at least a portion of the light of the second wavelength range through the pupil to illuminate a posterior region of the eyeball, wherein at least a portion of the light of the second wavelength range that illuminates the posterior region is scattered from the posterior region onto a sclera of the eyeball; 
 with a second optical sensor array, receiving at least a portion of the light scattered onto the sclera and producing a second image from the portion of the scattered light received thereby, the second image containing information relating to the alignment between the pars plana area and the first optical element of the first optics system; 
 with a processor, processing the second image to determine whether the first optical element is properly aligned with the pars plana area and to output a first control signal; and 
 with the at least a motorized stage mechanically coupled to the first optical element, receiving the first control signal and adjusting a spatial position of the first optical element to improve alignment between the first optical element and the pars plana area. 
 
     
     
       15. The method of  claim 14 , wherein the first optical element is a lens. 
     
     
       16. A non-mydriatic, non-contact u-WF photographic imaging system comprising:
 an illumination system comprising:
 at least a first light source, the first light source generating light of at least a first wavelength range; 
 a first optics system, the first optics system being configured to convert the light into a first light beam having a first predetermined shape and size, the first optics system including at least a first optical element that is spaced a predetermined distance away from an eyeball to avoid physical contact with the eyeball and with an eyelid of the eye, the first optical element being configured to couple the first light beam onto a pars plana area of an eyeball, wherein the first optics system includes at least an aperture element having an annular-arc shape to cause the first predetermined shape of the first light beam to substantially match a shape of the pars plana area of the eyeball, wherein the aperture element is configured to be positioned between the first optical element and the pars plana area of the eyeball; 
 at least a second light source of a second optics system, the second light source generating light of at least a second wavelength range during an alignment process of the first optics system between the pars plana area and the first optical element of the first optics system; 
 at least a second optical element of the second optics system arranged with respect to the second light source to couple at least a portion of the light of the second wavelength range through a pupil of the eye to illuminate a posterior region of the eyeball during the alignment process of the first optics system, wherein at least a portion of the light of the second wavelength range that illuminates the posterior region is scattered from the posterior region onto a sclera of the eyeball; 
 a second optical sensor array positioned to receive at least a portion of the light scattered onto the sclera and configured to produce a second image from the portion of the scattered light received thereby, the second image containing information relating to the alignment between the pars plana area and the first optical element of the first optics system; and 
 
 at least a processor configured to process the second image to determine whether the first optical element is properly aligned with the pars plana area and to output a first control signal; and adjust the arc-shaped aperture element to allow a width of an arc-shaped pattern formed by the arc-shaped aperture element to be adjusted to match the size of the pars plana area. 
 
     
     
       17. A method for performing non-mydriatic, non-contact ultra-widefield fundus (u-WF) photographic imaging of an eye, of comprising:
 with at least a first light source, generating light of at least a first wavelength range; 
 with a first optics system, converting the light into a first light beam having a first predetermined shape and size, the first optics system including at least a first optical element that is spaced a predetermined distance away from an eyeball to avoid physical contact with the eyeball and with an eyelid of the eye, wherein the first optics system further includes an aperture element having an annular-arc shape to cause the first predetermined shape of the first light beam to substantially match a shape of a pars plana area of the eyeball, wherein the aperture element is positioned between the first optical element and the pars plana area of the eyeball; 
 with the first optical element, coupling the first light beam onto the pars plana area of an eyeball; 
 with at least a second light source, generating light of at least a second wavelength range during an alignment process of the first optics system between the pars plana area and the first optical element of the first optics system; and 
 with at least a second optical element of a second optics system, coupling at least a portion of the light of the second wavelength range through a pupil of the eye to illuminate a posterior region of the eyeball, wherein at least a portion of the light of the second wavelength range that illuminates the posterior region is scattered from the posterior region onto a sclera of the eyeball; 
 with a second optical sensor array, receiving at least a portion of the light scattered onto the sclera and producing a second image from the portion of the scattered light received thereby, the second image containing information relating to the alignment between the pars plana area and the first optical element of the first optics system; 
 with a processor, processing the second image to determine whether the first optical element is properly aligned with the pars plana area and to output a first control signal; and 
 with the processor, adjusting the arc-shaped aperture element to allow a width of an arc-shaped pattern formed by the arc-shaped aperture element to be adjusted to match the size of the pars plana area.